The present disclosure relates to a dynamic stabilization device for bones or vertebrae comprising at least two bone anchoring elements which are connected by an elastic loop. The elastic loop allows a limited motion between the two bone anchoring elements and hence provides a dynamic stabilization of the two bones or vertebrae.
EP 0 669 109 B1 discloses a stabilization device comprising at least two monoaxial bone screws anchored in adjacent vertebrae and connected by a strap to transmit tensile forces between the respective vertebrae. A support body which is resistant to compression surrounds the strap between the bone screws to transmit compressive forces. The strap is fastened to the bone screws in a pre-stressed manner. If more than two bone screws are to be connected, this stabilization device is not easy to handle during surgery and the possibilities of adjusting the device are limited.
Another dynamic stabilization device comprising a bone screw and a flexible rod which is made of an elastomeric material is known from EP 1 364 622 A2. The elastic properties of the system which can be achieved between adjacent vertebrae are determined by the shape and the characteristics of the material of the rod. If a plurality of vertebrae shall be interconnected it is difficult to adapt the elastic properties over the length of the connection according to the actual requirements at the operation site. Furthermore, the receiving part and the shaft of the bone screw are monoaxially connected. This limits the possibility of adjustment of the position of the shaft relative to the rod.
US 2002/0133155 A1 discloses a spinal stabilization system with cross-coupled vertebral stabilizers incorporating spinal motion restriction. The cross-coupled members may assume different forms, including, among others, elastic bands.
U.S. Pat. No. 6,616,669 B2 discloses a device for tethering the spine which is a combination of an artificial strand threaded through channels defined in a set of blocks attached to the vertebral bodies on the convex side of the spine. The device is used to treat deformities by selectively constraining the growth in a portion of the convex side of the spine.
Based on the above, there is a need for a dynamic stabilization device for bones, in particular for vertebrae, which allows an easy adjustment according to the actual clinical requirements and which is simple and safe to be installed during surgery.